Twilio Voip Setup & Optimization (Inbound, Outbound, Sms, Multi-Device Ring)

We already have a basic VoIP system using Twilio SIP Domain and Zoiper, but it needs full configuration and optimization. The system currently receives calls, but with limitations: Caller ID shows the wrong number (forwarded number instead of the real client). Outbound calls from Zoiper fail. SMS sending/receiving not working. Only Zoiper rings — we need simultaneous ringing on multiple devices (store iPhone + Zoiper in Brazil). We’re looking for an experienced Twilio Developer / VoIP Engineer to fix these issues and make the system stable and professional. Current Setup: Store in the U.S. (AT&T mobile line). Call forwarding from iPhone → Twilio number → Zoiper (Brazil). SIP Domain created and working for inbound calls. Goals: Fix Caller ID – Show the real customer number. Enable Outbound Calls – Configure TwiML / Studio to call using Twilio number as caller ID. SMS Setup – Enable two-way SMS (via Conversations or another interface) and ensure 10DLC/A2P compliance. Simultaneous Ringing – Make iPhone and Zoiper ring together; first to answer gets the call. (Optional) Help with number porting from AT&T to Twilio and optimize Zoiper (codecs/NAT). Requirements: Proven experience with Twilio SIP, TwiML, Studio, and VoIP routing. Knowledge of sip/nat/stun, softphones (zoiper, linphone, twilio flex). Familiar with U.S. SMS compliance (A2P / 10DLC). Clear communication and simple documentation. Deliverables: Working inbound/outbound system with correct caller ID. Two-way SMS. Simultaneous ringing setup. Step-by-step documentation. Budget: Open to proposals (fixed price preferred).